[FIXED[ new member: surging issues [FIXED FOR REAL]

[lloydie]

Is it only imports that have the pairs system? Thought it was to do with emissions and not venting to open air?

Nope the later models have it too .
Tbe French model has a rite wombles up system with a canister by the oil filter !!

[VTR Phoenix]

That's good to know, I thought it was just the imports that had it given we don't have the emission test for bikes over here.

[roasty_duck]

So...

carbs out today and i have found.

main jet rear 175
main jet front 178
both the wrong way round

needle rear A1UD
needle front A1UE

Small split in front diaphragm, i had changed them with my spares a while back but it was surging before i changed them anyway so changed back.

Managed to break the choke off in the rear carb, put my new one in there.

So they where both wrong too. set them back to how they should be, bikes back together and its still surging at idle so im now thinking coils or caps.. still waiting on the cbr stick pack so can't rule that out, not taken for a test ride yet to see how it runs.

[roasty_duck]

small update nothing major..

got some plug caps and a set of carbs from squiffy

1 plug read 5k ohms other was at 13k ohms but both better than i had so swapped them, still surging, set about doing the carbs at 7:45pm in the dark with nothing but a bad headlamp for light...

managed to get tank airbox carbs all off and new set back on all bolts done up properly... in 40 minutes including breaks for a few pics, battling with slightly shorter fuel hoses and the headlamp died 30 minutes in so the last 10 was almost blind...

damn im good!

has miles more power now.. i tried to wheelie in 2nd with clutch and just spun the wheel like mad.. no longer need clutch for 2nd gear just snap the throttle and pull up.

bad news... its still surging

i got some coils from squiffy to do the stick pack mod for someone else but im tempted to pop them in quickly (are they a quick job to remove fairings?) and see what happens.

[roasty_duck]

Update:

fitted cbr stick pack
blocked pair system

still surging...

could i have skipped a tooth on cam?

previous owner told me he had a new auto cct fitted and it does look new.

[lloydie]

Have a look ,you've checked everything else

[tony.mon]

Update:

fitted cbr stick pack
blocked pair system

still surging...

could i have skipped a tooth on cam?

previous owner told me he had a new auto cct fitted and it does look new.

A cct? Hopefully both have been done.....
It doesnt take long to pull the fairing off, then tank, airbox, carbs, heatsheild below carbs.
Then undo the vertical bolts on the oil cooler mounting bracket, and remove rad support brackets from under the front head, rest the cooler on a rag on the front mudguard and you can then get going on checking the valve timing.
If you can get the larger of the two inspection caps off, of course....

[roasty_duck]

sorry yeah i meant both ccts,
waiting on a set of manuals from ade so ill leave it as it is for now and check when i fit them

[roasty_duck]

New update:

checked cdi and ecu. still surging.

today i checked valve clearances and cam timing.

valves where clearly done just before i bought the bike as theyre dead on spec.

timing was dead on

Now what.. is it time to admit defeat and sell it on to someone who has more time than i do

[VTR Phoenix]

I still believe that the surging is fuel/air related. Have you checked for slight blockages in the fuel supply lines, the air filters, fuel filters. Have you checked all the filters in the airbox, do you have a T piece on the vacuum line that goes to the petcock that isn't blocked off.

Get it on the stand, remove airbox, spin tank round, get it upto the revs where it stumbles/surges and watch the carbs and listen to the engine, I'd hazard a guess the front cylinder misses during the surging.

[roasty_duck]

its had 3 sets of carbs on it now with their own fuel lines

it will do an indicated 150mph but i cant hold a steady speed or it surges.

vacuum line from front is blocked off, it still had the bolt in when i bought it.

[VTR Phoenix]

Ok, what speed/revs does it surge or is it just holding steady throttle at any speed/revs?

[roasty_duck]

steady throttle at any revs, twist the throttle it doesnt miss a beat, hold it steady and surges again, it makes riding a nightmare, more so when im riding a bit speedy on long bends as it bounces around whilst leaning.

[VTR Phoenix]

Have you tested your tps?

[roasty_duck]

3 sets of carbs been in and all 3 tps set to 500-502